Compression of air using an hydraulic air compressor (HAC) is generally known. In Richardson, U.S. Pat. No. 4,797,563, the disclosure of which is hereby incorporated by reference, discloses a HAC to compress air which is provided to the burners of a turbine to generate electrical power. According to this reference, air is drawn into the down shaft through open pipes into the flowing water to be compressed. The compressed air and water emerge from the shaft at a tunnel where the compressed air liberates from the water and is conducted to a turbine. Richardson does not show any means to forcible entrain air or for efficiently entraining air into the flowing liquid for compression thereof.
In Angle, U.S. Pat. No. 5,099,648, a HAC is also disclosed which, similarly to Richardson '563 does not provide any means to forcibly entrain air into the liquid for compression thereof.
Accordingly, a drawback of the type of systems discussed above is that the volume of air for compression relies upon a configuration to naturally draw air into the liquid flow as the volume of air to be compressed. Means are not disclosed to increase the volume of air to be compressed to provide for more versatility and efficiency in a HAC or system incorporated the same. Still further, these systems provide no convenient means to control either or both of the flow of liquid through the HAC or the volume of compressed air produced. It would be desirable to provide means to control the flow of liquid and the volume of air produced by the HAC.
Still further, these prior HACs are subject to slug flow in their down shafts which can result in blowback of compressed air up the down shaft.
The systems described above also provide no means to aerobically treat effluence such as waste water, sewage effluent or the like.
It would be desirable to provide a more versatile and efficient HAC to compress air for any purpose such as to provide combustion air to a burner or a fuel-fired turbine for the production of steam, work or electricity. It would also be desirable to provide a system incorporating a HAC to provide compressed air according to the foregoing which also uses and aerobically treats waste water such as sewage effluent or the like.
Regarding treatment of waste, it has been known in the prior art to treat effluent such as domestic and industrial waste through aeration to reduce the biologic oxygen demand (BOD) imposed by biodegradation of the waste on the environment. For treatment of sewage it has been known to provide large surface area sludge ponds, aerators, sprinklers and bubblers to supply the BOD for biodegradation of the waste. It has also been known to provide vertical shaft bioreactors as described in Pollock, U.S. Pat. No. 5,660,724. In vertical shaft bioreactors, the effluent is supplied at the top of a vertical shaft to flow downwardly to the bottom. At the bottom of the vertical shaft, air may be injected. From the bottom a riser returns the effluent for recirculation. Air is injected at the bottom of the riser to not only aerate the effluent but to create an air lift for circulation of the effluent. These systems aerobically treat the effluent but do not provide any byproduct such as compressed air which can be utilized to produce energy or work. Further injection of air at the bottom of the vertical shaft cannot provide for any significant compression thereof.
It would be highly desirable if a system could be devised which could not only aerobically treat and agitate a waste water effluent but which could also produce a byproduct of compressed air which can be utilized to, for example, supply combustion air to a burner or a turbine.